Answer:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as

Now by putting the values in the above equation ,then we get

η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
How do you get out of a room with only a mirror and a table?
Look in the mirror you see what you saw, use the saw to cut the table, half and half makes a hole, jump in it.
Thought you would like that.
in cgs system, plank's constant= h=6.626 x10⁻²⁶ erg s
Value of Plank's constant in SI system= 6.626 x10⁻³⁴ Js
now 1 Joule= 10⁷ ergs
so h= 6.626 x10⁻³⁴ Js (10⁷ ergs/1J)
h=6.626 x10⁻²⁷ erg s
Its simple use formuila ,
PV=nRT
n,R is constant as the both have same moles.
so,
(p1v1)/T1 = (p2v2)/T2
so, 128.53338kpa